Hi We walked from Resy to Theodul Hut, via Plan Maison and the Theodul-Pass.see this map…
It was quite poor weather when we did it; with rain, thick new snow, and some fog too. see photo….

We did not use a guide and did not need a rope to get up to the Theodul Hut, however we did use a rope to walk down the glacier from Theodul Hut to Trockensteg (even though it is supposed to quite a safe glacier, we didn’t take the risk)